In the normal case, a truck operator's primary responsibility is to drive the tractor/trailer, while a truck mechanic performs repair and maintenance on such tractor/trailers. However, the truck operator is often called upon to perform minor duties such as disconnecting the tractor from the trailer, checking the tire air pressure, and raising and lowering the hydraulic landing gear when a trailer is disconnected from a tractor. These duties are separate from the repair and maintenance duties performed by a truck mechanic or the like.
Unlike a mechanic, truck operators do not have a full complement of tools available for performing their duties. Most of the minor duties performed by the truck operator are performed by hand. For example, the truck operator is often called on to disconnect or uncouple a fifth wheel pin employed to connect the trailer to the tractor. The fifth wheel pin is located between the tractor and the trailer above the rear tires of the tractor. The truck operator is expected to bend down and reach between the tractor and the trailer past one set of rear tires to pull the fifth wheel pin. This action requires operators to contort themselves into an awkward position while pulling the pin and often results in the operators straining any number of body parts, such as shoulders, elbows, and wrists and especially their backs.
While most of the non-driving duties of the operator are performed by hand, one tool commonly employed by truck operators is a "butt bar." A butt bar is a straight piece of metal approximately one to two feet in length with which the operator bangs on the tires of the tractor/trailer to test the air pressure in the tires.
Additionally, it is believed that some operators have attached a hook to their butt bars; these hooks allow the operator to use the butt bar to pull the fifth wheel pin, but this is only a marginally effective tool because butt bars do not have a handle; the operators must therefore grip the bar with two hands and press their faces against the trailer to develop sufficient leverage on "tough pulls." Obviously, the truck operator must still bend over into an awkward position to pull the the fifth wheel pin.
Also, tools having a thin shaft and a hook on the end thereof have been used to pull fifth wheel pins, but these tools are awkward to use and store and are used only for a single purpose: removing fifth wheel pins.
Another duty performed by truck operators is the raising and lower of hydraulic landing gear on which the trailer rests when it is not hooked up to the tractor. As mentioned, these landing gear are often hydraulically operated. In some cases, however, the landing gear "stick" and do not raise properly. This sticking is the result of debris on the exposed leg and/or problems with the hydraulic system. As a mechanic is not always available, when the landing gear stick, it is often necessary to loosen the sticky landing gear by prying on the ground contacting portion of the landing gear with a screw driver, crow bar, or the like to raise the landing gear an inch or so. Butt bars often have a flattened tip for this purpose. Once the landing gear is so raised a small distance, the hydraulic system is usually able to raise the landing gear the remaining portion.